Choosing the right compost needn’t be a challenge. Follow Amateur Gardening’s easy-to-understand guide and your garden will be bloomin’ lovely!
Potting-on compost (John Innes No. 2)
When young plants are ready to be transferred into bigger pots, look for a potting-on compost – such as a John Innes No. 2.
These will contain sufficient fertiliser to keep your plants fed for up to six weeks, encouraging them to produce healthy top-growth and strong root systems – but not so much that it might damage roots.
Mature Plant Compost (John Innes No.3)
Over the years, mature plants that live in containers outdoors can need a bit of TLC. Their compost can become compacted and depleted of nutrients, leading to poor growth and, in severe cases, leaf yellowing and increased susceptibility to pests and diseases.
As multi-purpose composts are only designed to be in use for six to twelve months, never use these mixes for long-term plantings. Choose a John Innes No. 3 as it’s specially formulated for plants that will be in the same container for several years.
It won’t degrade so fast, but after 6-8 weeks you may need to start feeding plants again.
8. Ericaceous compost
Plants such as rhododendron, azalea, camellia, acer, magniloa, skimmia and heather are the horticultural world’s equivalent of children who are fussy eaters. They’re picky about what they put their roots into, detesting soil with lime in it, and insisting on acidic growing media. Ericaceous compost is the name given to blends that are suitable for acid-lovers. They’re often high-peat mixes, with a peat content of between 60-100 per cent.
Ericaceous compost can be mixed into the soil when planting acid-lovers in borders, and for top-dressing (spreading on the soil surface) of plants that prefer acidic soil.
This compost is only suitable for plants that need acid soil.
9. Containers and hanging baskets compost
As mentioned earlier, multi-purpose compost works fine in pots, hanging baskets and containers. But if you often forget to water (who doesn’t), or your baskets and tubs are in a very hot, sunny position, it’s worth going for a specific pot and basket compost.
The key ingredient in most of these products is a water-retaining gel, which soaks up moisture when you water and releases it direct to the roots as the compost starts to dry.
Miracle-Gro Moisture Control compost is a popular choice for pots and baskets as it absorbs twice as much water as ordinary compost. This, says Miracle-Gro, leads to 50 per cent less watering than standard compost – and it contains six months’ fertiliser, too.
10. Growing bag
Growing bags take the hassle out of planting edibles – the bag contains a specially-formulated blend of compost, nutrients and water-retaining gel. They’re ideal for tomatoes, cucumbers, peppers, strawberries, courgettes and salad crops. The key to success is to choose the biggest, fattest bag you can find: the fatter the bag, the more compost it contains and the deeper your plant’s roots will be able to go. Cheap, thin bags can dry out quickly on hot summer days, with serious consequences for developing fruit and veg. Most growing bags will accommodate a host of crops, but the one shown here is enriched with seaweed extract, which helps to improve root growth and yield on tomatoes.